BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to recording heads and inkjet recording apparatuses.
Description of the Related Art
[0002] Conventional inkjet recording apparatuses are known that employ a recording head
provided with a plurality of discharge opening array units including discharge opening
arrays in which a plurality of discharge openings for discharging ink is arranged.
In the inkjet recording apparatuses, while the recording head performs forward and
backward scans with respect to a recording medium, ink is discharged to form an image
on the recording medium.
[0003] It is known that in such an inkjet recording apparatus configured to perform forward
and backward scans, a color in a region recorded by a forward scan on a recording
medium can differ from a color in a region recorded by a backward scan on the recording
medium, and the color difference can cause image quality deteriorations. The color
difference will be described in detail below focusing only on black and yellow inks.
In a case of using a recording head that includes only one black ink discharge opening
array unit and one yellow ink discharge opening array unit, black and yellow inks
are applied in this order to a region recorded by one of forward and backward scans,
whereas yellow and black inks are applied in this order to a region recorded by the
other one of the forward and backward scans. The difference in the order of application
of inks between the forward and backward scans causes a color difference between the
forward and backward recorded regions.
[0004] To solve this issue, Japanese Patent Application Laid-Open No.
2010-046904 discusses a recording head including a plurality of discharge opening array units
arranged to reduce the color difference between the forward and backward recorded
regions described above. Specifically, in Fig. 9 in Japanese Patent Application Laid-Open
No.
2010-046904, one yellow ink discharge opening array unit and two black ink discharge opening
array units are provided, and the black ink discharge opening array units and the
yellow ink discharge opening array unit are arranged symmetrically. Use of such a
recording head enables application of black, yellow, and black inks in this order
in both forward and backward scans to reduce a color difference between the forward
and backward recorded regions.
[0005] Further, many conventional inkjet recording apparatuses use inks of four colors in
total including basic colors (three primary colors), which are cyan, magenta, and
yellow, and a black ink. However, in recent years, use of an ink of another color
depending on the purpose in addition to the inks of four colors has been known. For
example, when cyan and magenta inks having a low lightness are applied in a superimposing
manner onto a recording medium to reproduce a blue hue, a problem arises that an image
with notable graininess is recorded. The problem of graininess is solved by using
a light cyan ink and a light magenta ink each having substantially the same hue as
the hues of cyan and magenta and having a higher lightness. However, use of the inks
of two colors in addition to the inks of four colors leads to an increase in apparatus
size and costs. Japanese Patent Application Laid-Open No.
2002-154240 discusses use of a light blue ink having a hue between the hues of cyan and magenta
and having a higher lightness than the lightness of cyan and the lightness of magenta.
Use of the light blue ink enables recording with less visible graininess in the blue
hue, which is easily visually recognizable, without an increase in apparatus size
and costs.
[0006] However, when the discharge opening array unit for discharging the light blue ink
discussed in Japanese Patent Application Laid-Open No.
2002-154240 is further added in the recording head discussed in Japanese Patent Application Laid-Open
No.
2010-046904 in which the discharge opening array units for the inks of different colors are arranged
symmetrically, a problem described below arises.
[0007] First, a case in which only one light blue ink discharge opening array unit is arranged
will be described below. In order to reduce a color difference between the forward
and backward recorded regions described above, it is desirable to arrange the light
blue ink discharge opening array unit between two black ink discharge opening array
units. This arrangement enables application of black, light blue, and black inks in
this order in both forward and backward scans.
[0008] However, in the above-described arrangement, the distance between the two black ink
discharge opening array units for the black ink, which has the lowest lightness among
the colors, becomes relatively long. This can cause a problem that image quality deteriorations
are visible when the recording head is attached at a tilt to the recording apparatus
or when scans performed by the recording head are tilted.
[0009] For example, when the recording head in which the discharge opening array units of
black, yellow, and black inks are arranged in this order as illustrated in Fig. 9
in Japanese Patent Application Laid-Open No.
2010-046904 further includes the light blue ink discharge opening array unit arranged as described
above, not only the yellow ink discharge opening array unit but also the light blue
ink discharge opening array unit is located between the two black ink discharge opening
array units. The increase in the number of discharge opening array units located between
the two black ink discharge opening array units results in an increase in the distance
between the black ink discharge opening array units.
[0010] The greater the distance between the two discharge opening array units is, the more
significant the deviation of ink landing positions becomes when the recording head
is attached at a tilt to the recording apparatus or when scans performed by the recording
head are tilted. A deviation of landing positions of the black ink, which has the
lowest lightness, causes a more significant deterioration in image quality than those
of other color inks. Thus, if the light blue ink discharge opening array unit is arranged
between the two black ink discharge opening array units and increases the distance
between the discharge opening array unit for the black ink, which has the lowest lightness,
a deviation of ink landing positions can cause a significant deterioration in image
quality.
[0011] If two light blue ink discharge opening array units are provided and two black ink
discharge opening array units are arranged between the two light blue ink discharge
opening array units, the distance between the two black ink discharge opening array
units is decreased while the black and light blue inks are applied in the same order
in both forward and backward scans. However, providing two discharge opening array
units when one discharge opening array unit is sufficient can cause an unnecessary
increase in the size of the recording head.
[0012] US 2009/0174741 describes an ink jet recording head which includes a large nozzle array including
a plurality of ejection outlets for ejecting ink, a small nozzle array including a
plurality of ejection outlets each having an opening area smaller than an opening
area of ejection outlets of the large nozzle array. The ink jet recording head is
mountable to an ink jet recording apparatus which is capable of causing the ink jet
recording head without image formation on a recording material. The large nozzle array
is supplied with light ink consisting of yellow, light cyan or light magenta ink,
and the small nozzle array is supplied with dark ink consisting of cyan, magenta or
black ink. The number of ejections of the dark ink is larger than the number of ejections
of the light ink.
SUMMARY OF THE INVENTION
[0013] The present invention is directed to a recording head capable of reducing a color
difference between forward and backward scans while reducing image quality deteriorations
resulting from deviations of ink landing positions.
[0014] According to a first aspect of the present invention, there is provided a recording
head as specified in claims 1 to 14. According to a second aspect of the present invention,
there is provided an inkjet recording apparatus as specified in claims 15 and 16.
[0015] Further features of the present invention will become apparent from the following
description of exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
Fig. 1 is a perspective view illustrating an image recording apparatus according to
a first exemplary embodiment.
Fig. 2 schematically illustrates a recording control system according to the first
exemplary embodiment.
Fig. 3 illustrates a process of data processing according to the first exemplary embodiment.
Figs. 4A and 4B illustrate ink recording rates in respective density gradations according
to the first exemplary embodiment.
Fig. 5 is a perspective view illustrating a recording head according to the first
exemplary embodiment.
Fig. 6 illustrates a surface of a chip in a recording head according to the first
exemplary embodiment.
Figs. 7A, 7B, and 7C are see-through views each illustrating a region around discharge
openings in a recording head according to the first exemplary embodiment.
Figs. 8A and 8B illustrate a color difference between forward and backward scans.
Figs. 9A and 9B illustrate image quality deteriorations resulting from a deviation
of ink landing positions.
Fig. 10 illustrates a surface of a chip in a recording head according to a second
exemplary embodiment.
Fig. 11 is a see-through view illustrating a region around discharge openings in a
recording head according to the second exemplary embodiment.
DESCRIPTION OF THE EMBODIMENTS
[0017] A first exemplary embodiment of the present invention will be described in detail
below with reference to the drawings.
[0018] Fig. 1 schematically illustrates an internal configuration of an inkjet recording
apparatus 1000 according to the present exemplary embodiment. In Fig. 1, the inkjet
recording apparatus 1000 with an upper cover opened is illustrated.
[0019] The inkjet recording apparatus (hereinafter, sometimes referred to also as "printer"
or "recording apparatus") 1000 according to the present exemplary embodiment includes
a carriage 5 which is moved forward and backward (performs forward and backward scans)
along an X-direction (intersecting direction). On the carriage 5 is mounted a recording
head 1 described below. In the present exemplary embodiment, the moving speed (scan
speed) of the carriage 5 and the recording head 1 is approximately 25 inches/second.
While the carriage 5 and the recording head 1 are moved forward and backward, ink
is discharged from the recording head 1 to record an image onto a recording medium.
[0020] The recording medium is fed from a sheet feeding tray of the printer 1000 and conveyed
in a sub-scan direction which intersects with the X-direction. In the present exemplary
embodiment, a recording medium is conveyed at approximately 5 inches/second.
[0021] In the present exemplary embodiment, the scans by the recording head 1 and the conveying
of a recording medium are repeated alternately as described above to complete recording
on the single sheet of recording medium. In the present exemplary embodiment, either
one of a one-pass recording method, in which recording on a unit region on a recording
medium is completed by a single scan, and a multipass recording method, in which recording
on a unit region is completed by a plurality of scans, can be used.
[0022] Further, the thickness of a sheet used in the present exemplary embodiment is approximately
0.3 mm, and in this case, the distance between the recording head 1 and the sheet
in a height direction is approximately 1.0 mm. An upper portion of the printer 1000
includes a scanner 4 for scanning an image to be recorded. The scanner 4 is integrated
with an upper cover of the printer 1000.
[0023] Fig. 2 is a block diagram schematically illustrating the configuration of a control
system in the printer 1000 according to the present exemplary embodiment. A main control
unit 300 includes a central processing unit (CPU) 301, a read-only memory (ROM) 302,
a random access memory (RAM) 303, and an input/output port 304. The CPU 301 executes
processing such as calculation, selection, determination, and control. The ROM 302
stores control programs, etc. to be executed by the CPU 301. The RAM 303 is used as
a buffer, etc. for recording data. Further, the ROM 302 also stores mask patterns,
etc. described below. The input/output port 304 is connected to driving circuits 305,
306, 307, and 308 for respectively driving a conveying motor (LF motor) 309, a carriage
motor (CR motor) 310, the recording head 1, and an actuator of a disconnect device
for disconnecting a recording medium, etc. Further, the main control unit 300 is connected
to a personal computer (PC) 312, which is a host computer, via an interface circuit
311.
(Data Generation Processing)
[0024] Fig. 3 is a flow chart illustrating a process of generating recording data for use
in recording executed by the CPU 301 according to a control program in the present
exemplary embodiment. The control program is stored in advance in the ROM 302.
[0025] Input image data is red-green-blue (RGB) signals of eight bits per color which has
a resolution of 600 dpi and 256 gradations per pixel. The data is first transmitted
to a color correction processing unit 401 to undergo processing for associating a
color space expressed by the host PC 312, such as a standard RGB (sRGB) color space,
with a color space that can be expressed by the printer 1000. Specifically, 8-bit,
256-value RGB signals are converted into 8-bit, 256-value RGB signals by referencing
a three-dimensional look-up table (LUT) stored in advance in the ROM 302.
[0026] Next, an ink color separation processing unit 402 converts data generated by the
color correction processing unit 401 into data corresponding to ink colors used by
the recording apparatus 1000. Specifically, 8-bit, 256-value RGB signals are converted
into 8-bit density signals of the respective ink colors by referencing a three-dimensional
LUT stored in advance in the ROM 302.
[0027] The separated data of each ink color is input to a gamma correction processing unit
403, and density value correction is performed for each ink color. Gamma correction
is a correction performed so that densities of input data and optical densities of
an image expressed on a recording medium have a linear relationship. Specifically,
8-bit, 256-value density data of each ink color is converted into 8-bit, 256-value
density data by referencing a one-dimensional LUT stored in advance in the ROM 302.
[0028] Thereafter, a quantization processing unit 404 performs quantization processing on
the 8-bit, 256-value density data of each ink color to generate 2-bit, 4-value quantized
data of each ink color. In the present exemplary embodiment, a method for the quantization
processing is not particularly limited, and a dither method, an error diffusion method,
etc. can be used.
[0029] Next, the quantized data is transmitted to an index development processing unit 405
and converted into 1-bit binary data. Specifically, an index pattern that defines
the number and positions of ink to be discharged with respect to 2 pixels × 2 pixels
= 4 pixels according to values of quantized data for one pixel group including 2 pixels
× 2 pixels is used to generate binary data which defines whether to discharge or not
discharge each ink with respect to each pixel. The index pattern is stored in advance
in the ROM 302.
[0030] Thereafter, the binary data is transmitted to a distribution processing unit 406,
and binary data is distributed to a plurality of scans with respect to a unit region.
Specifically, 1-bit binary recording data for use in a plurality of scans is generated
for each of the scans using a plurality of mask patterns corresponding to the plurality
of scans and defining whether to discharge or not discharge ink with respect to each
pixel. The plurality of mask patterns is stored in advance in the ROM 302. Further,
in the case of the recording using the single-pass recording method, the processing
of the distribution processing unit 406 is omitted.
[0031] While the foregoing describes that the CPU 301 in the printer 1000 executes the processing
of every one of the units 401 to 406, a CPU (not illustrated) in the PC 312 can execute
some or all of the processing of the units 401 to 406.
(Hue and Brightness of Ink)
[0032] In the present exemplary embodiment, recording is performed using a light blue ink
in addition to cyan, magenta, yellow, and black inks.
[0033] The light blue ink used in the present exemplary embodiment has a relatively high
lightness (low density) and a relatively close hue to a blue hue reproduced by a mixture
of equal amounts of cyan and magenta inks. Specifically, the light blue ink used in
the present exemplary embodiment satisfies the conditions that the hue of the light
blue is between the hues of the cyan and magenta inks and the lightness of the light
blue is higher than the lightness of the cyan ink and the lightness of the magenta
ink.
[0034] Use of the light blue ink that satisfies the above-described conditions enables reproduction
of the blue hue without superimposing the cyan and magenta inks in the recording of
a low-density (inks are discharged in small amounts) image. This enables recording
of an image with less graininess in the blue hue.
[0035] Hereinafter, the hue angles of the cyan, magenta, light blue, black, and yellow inks
will be denoted by h1, h2, h3, h4, and h5, respectively, and the lightnesses of the
cyan, magenta, light blue, black, and yellow inks will be denoted by L1, L2, L3, L4,
and L5, respectively. The hue angles and lightnesses of the respective color inks
used in the present exemplary embodiment are shown in (Table 1).
(Table 1)
|
h |
L |
Cyan |
h1 = 228 |
L1 = 63 |
Magenta |
h2 = 348 |
L2 = 61 |
Light Blue |
h3 = 299 |
L3 = 68 |
Black |
h4 = 229 |
L4 = 36 |
Yellow |
h5 = 92 |
L5 = 90 |
[0036] From (Table 1) it is understood that the light blue ink used in the present exemplary
embodiment satisfies the conditions that the hue angle h3 of the light blue is between
the hue angle h1 of the cyan ink and the hue angle h2 of the magenta ink and the lightness
L3 of the light blue is higher than the lightness L1 of the cyan ink and the lightness
L2 of the magenta ink. Thus, it is determined that:
h1 < h3 < h2,
L3 > L1, and
L3 > L2.
Furthermore, lightness L4 of the black ink is lower than the lightness of the other
ink, and thus it is determined that:
L4 < L1,
L4 < L2,
L4 < L3, and
L4 < L5.
In particular, the lightness L1 of the cyan ink is higher than the lightness L4 of
the black ink, and the lightness L2 of the magenta ink is higher than the lightness
L4 of the black ink, and thus it is determined that:
L3 > L1 > L4, and
L3 > L2 > L4.
This disclosure is not restricted to the inks being of a particular color, such that:
the cyan ink is an example of a first ink;
the magenta ink is an example of a second ink;
the light blue ink is an example of a third ink;
the black ink is an example of a fourth ink; and
the yellow ink is an example of a fifth ink.
(How Respective Color Inks are Used)
[0037] The following describes how the respective color inks are used.
[0038] Fig. 4A illustrates the discharge amount (recording rate) of each color ink used
to reproduce each density gradation from white to black via blue on a blue line in
the present exemplary embodiment.
[0039] First, in a low-density region close to white, in order to prevent a decrease in
graininess which results from application of the cyan and magenta inks in a superimposing
manner, the discharge amount of the light blue ink is increased to increase the density.
Then, in an intermediate density region close to blue, it is no longer possible to
reproduce a density with the light blue ink, so the discharge amounts of the cyan
and magenta inks are increased while the discharge amount of the light blue ink is
decreased to increase the density. Then, in a high-density region close to black,
the discharge amount of the black ink is increased while the discharge amounts of
the cyan and magenta inks are decreased to reproduce a density close to black.
[0040] Further, Fig. 4B illustrates the discharge amount (recording rate) of each color
ink used to reproduce each density gradation from white to black via yellow on a yellow
line in the present exemplary embodiment.
[0041] In low to intermediate density regions from white to yellow, the discharge amount
of the yellow ink is increased to increase the density. Further, in a region from
the intermediate density region toward black, since simultaneous use of yellow, which
has a high lightness, and black, which has a low lightness, can lead to image quality
deteriorations, the cyan, magenta, and light blue inks are used while the discharge
amount of the yellow ink is decreased to increase the density. Then, lastly, the discharge
amount of the black ink is increased to reproduce a density close to black.
(Recording Head)
[0042] Fig. 5 is a perspective view illustrating the recording head 1 used in the present
exemplary embodiment.
[0043] The recording head 1 according to the present exemplary embodiment includes an ink
supply unit 2 and an ink discharging unit 3 which are integrated. The ink supply unit
2 includes a holding member 2A which holds an ink tank (not illustrated) for supplying
ink.
[0044] The ink discharging unit 3 includes a chip (Bk chip) 10 for discharging a pigment
black ink and a chip (Cl chip) 20 for discharging a dye ink described below. The following
description focuses on the Cl chip 20.
[0045] Fig. 6 is an enlarged view illustrating the Cl chip 20 in the recording head 1 according
to the present exemplary embodiment. Further, Figs. 7A, 7B, and 7C illustrate the
internal configurations of discharge opening array units (discharge opening array
means) according to the present exemplary embodiment.
[0046] The Cl chip 20 according to the present exemplary embodiment includes eight common
liquid chambers 21 in total connected to the ink supply unit 2. In each one of the
common liquid chambers 21 is formed one discharge opening array unit LG1. Each of
the discharge opening array units LG1 includes a plurality of discharge opening arrays,
and the diameters (discharge opening diameters) of discharge openings arranged in
the respective discharge opening arrays differ among the discharge opening array units
LG1.
[0047] Each of the discharge openings in the Cl chip 20 is opened with respect to a nozzle
plate connected to a member (hereinafter, also referred to as "common liquid chamber
forming member") forming the common liquid chambers 21. The common liquid chamber
forming member includes thermoelectric conversion elements (hereinafter, also referred
to as "heaters") situated to face the respective discharge openings.
[0048] The discharge opening array units LG1 in the Cl chip 20 will be described in detail
below.
1. Yellow Ink Discharge Opening Array Unit
[0049] The Cl chip 20 according to the present exemplary embodiment includes only one yellow
ink discharge opening array unit (LG1 (Y)). The yellow ink discharge opening array
unit LG1 (Y) includes two discharge opening arrays.
[0050] Fig. 7A illustrates the yellow ink discharge opening array unit LG1 (Y) in detail.
[0051] In the yellow ink discharge opening array unit LG1 (Y), the two discharge opening
arrays are provided on the respective sides of the common liquid chamber 21. The discharge
opening arrays include relatively large discharge openings 22 each of which has a
diameter of approximately 16 µm and through which an ink droplet of approximately
5 pl is discharged. In each of the discharge opening arrays, 264 discharge openings
22 are arranged at 600-dpi intervals (approximately 42.3 µm) in a Y-direction. Further,
the discharge opening arrays are staggered at 1200-dpi intervals (approximately 21.2
µm) in the Y-direction.
[0052] Further, as described above, heaters 28 are provided in positions facing the discharge
openings 22. Further, bubble generation chambers 25 are provided to respectively surround
the heaters 28, and ink flow paths 26 are formed to connect the bubble generation
chambers 25 to the common liquid chamber 21. Further, foreign substance blocking columns
27 are provided to block foreign substances contained in the ink from entering the
ink flow paths 26. The configurations of the heaters 28, the bubble generation chambers
25, the ink flow paths 26, and the foreign substance blocking columns 27 are similar
to those in other discharge opening array units LG1, so description thereof will be
omitted hereinafter.
2. Black Ink Discharge Opening Array Unit, Cyan Ink Discharge Opening Array Unit,
and Magenta Ink Discharge Opening Array Unit
[0053] The Cl chip 20 according to the present exemplary embodiment includes two black ink
discharge opening array units (LG1 (K1), LG1 (K2)). Each of the black ink discharge
opening array units LG1 (K1) and LG1 (K2) includes two discharge opening arrays.
[0054] Fig. 7B illustrates the black ink discharge opening array unit LG1 (K1) in detail.
[0055] In the black ink discharge opening array unit LG1 (K1), one of the discharge opening
arrays is provided on one side (left side) of the common liquid chamber 21. The discharge
opening array includes relatively large discharge openings 22 each of which has a
diameter of approximately 16 µm and through which an ink droplet of approximately
5 pl is discharged. Further, the other one of the discharge opening arrays is provided
on the other side (right side) of the common liquid chamber 21. The discharge opening
array includes moderate discharge openings 24 each of which has a diameter of approximately
12 µm and through which an ink droplet of approximately 2 pl is discharged. In the
respective discharge opening arrays, 264 discharge openings 22 and 264 discharge openings
24 are respectively arranged at 600-dpi intervals (approximately 42.3 µm) in the Y-direction.
Further, the discharge opening arrays are staggered at 1200-dpi intervals (approximately
21.2 µm) in the Y-direction.
[0056] As in the case of the discharge opening array unit LG1 (K1), the black ink discharge
opening array unit LG1 (K2) includes a discharge opening array including discharge
openings each having a diameter of approximately 16 µm and a discharge opening array
including discharge openings each having a diameter of approximately 12 µm. The two
discharge opening array units LG1 (K1) and LG1 (K2) are different in that the locations
of the two discharge opening arrays in the X-direction in the discharge opening array
units LG1 (K1) and LG1 (K2) are opposite. Further, the two discharge opening arrays
having the discharge openings of the same diameter in the discharge opening array
units LG1 (K1) and LG1 (K2) are staggered at 1200-dpi intervals (approximately 21.2
µm) in the Y-direction.
[0057] A cyan ink discharge opening array unit LG1 (C1) and a magenta ink discharge opening
array unit LG1 (M1) each have a similar configuration to the configuration of the
black ink discharge opening array unit LG1 (K1). Further, a cyan ink discharge opening
array unit LG1 (C2) and a magenta ink discharge opening array unit LG1 (M2) each have
a similar configuration to the configuration of the black ink discharge opening array
unit LG1 (K2).
3. Light Blue Ink Discharge Opening Array Unit
[0058] The Cl chip 20 according to the present exemplary embodiment includes one light blue
ink discharge opening array unit (LG1 (LB)). The light blue ink discharge opening
array unit LG1 (LB) includes four discharge opening arrays.
[0059] Fig. 7C illustrates the light blue ink discharge opening array unit LG1 (LB) in detail.
[0060] As illustrated in Fig. 7C, in the light blue ink discharge opening array unit LG1
(LB), two of the discharge opening arrays are provided on one side (left side) of
the common liquid chamber 21. One of the two discharge opening arrays includes moderate
discharge openings 24 each of which has a diameter of approximately 12 µm and through
which an ink droplet of approximately 2 pl is discharged, and is situated close to
the common liquid chamber 21. The other one of the two discharge opening arrays includes
relatively small discharge openings 23 each of which has a diameter of approximately
9 µm and through which an ink droplet of approximately 1 pl is discharged, and is
situated far from the common liquid chamber 21. Similarly, the other two of the discharge
opening arrays are provided on the other side (right side) of the common liquid chamber
21, and the discharge opening diameters of the two discharge opening arrays are approximately
12 µm and approximately 9 µm, respectively. As described above, the light blue ink
discharge opening array unit LG1 (LB) includes four discharge opening arrays in total,
including two discharge opening arrays with a discharge opening diameter of approximately
12 µm and two discharge opening arrays with a discharge opening diameter of approximately
9 µm.
[0061] Each of the discharge opening arrays includes 264 discharge openings 23 or 24 arranged
at 600-dpi intervals (approximately 42.3 µm) in the Y-direction. Further, the two
discharge opening arrays situated on the same side with respect to the common liquid
chamber 21 (the discharge opening array with a discharge opening diameter of approximately
16 µm and the discharge opening array with a discharge opening diameter of approximately
12 µm) are staggered at 1200-dpi intervals (approximately 10.6 µm) in the Y-direction.
4. Arrangement Order of Discharge Opening Array Units in Chip
[0062] As illustrated in Fig. 6, in the chip 20 according to the present exemplary embodiment,
the cyan ink discharge opening array unit LG1 (C1), the magenta ink discharge opening
array unit LG1 (M1), the light blue ink discharge opening array unit LG1 (LB), the
black ink discharge opening array unit LG1 (K1), the yellow ink discharge opening
array unit LG1 (Y), the black ink discharge opening array unit LG1 (K2), the magenta
ink discharge opening array unit LG1 (M2), and the cyan ink discharge opening array
unit LG1 (C2) are arranged in this order from the left.
[0063] The following describes the reason why the discharge opening array units are arranged
in the above-described order.
[0064] In the present exemplary embodiment, the arrangement order of the discharge opening
array units is determined based on two points. One of the points is to reduce a color
difference between forward and backward scans. The other one of the points is to reduce
image quality deteriorations resulting from deviations of ink landing positions. First,
the color difference between forward and backward scans and the image quality deteriorations
resulting from deviations of ink landing positions will be described below.
(1) Difference in Color between Forward and Backward Scans
[0065] Fig. 8A illustrates a recording head including two discharge opening array units
which are a discharge opening array unit LG (Color 1) for Color 1 and a discharge
opening array unit LG (Color 2) for Color 2, which is different from Color 1. Further,
Fig. 8B illustrates the appearances of landed ink droplets in the recording performed
by forward and backward scans using the recording head illustrated in Fig. 8A.
[0066] In the case where the recording head illustrated in Fig. 8A is used, inks of Colors
2 and 1 are discharged in this order in forward scans, and inks of Colors 1 and 2
are discharged in this order in backward scans, with respect to the same position
on a recording medium in a scan direction.
[0067] If the inks of Colors 1 and 2 are discharged in small amounts and thus are not discharged
onto the same region on a recording medium P, dots 33 of Color 1 and dots 34 of Color
2 are not superimposed, as illustrated in Fig. 8B. Thus, although the inks are applied
in different order in forward and backward scans, landed dots exhibit the same appearance,
so reproduced colors are substantially the same.
[0068] However, if the inks of Colors 1 and 2 are discharged in large amounts and thus are
discharged onto the same region, different colors are reproduced in forward and backward
scans. As illustrated in Fig. 8B, in the forward scan, the ink of Color 2 is applied
onto a recording medium P to form dots 34, and then the ink of Color 1 is applied
onto the dots 34. Since a dye ink moves around previously-formed dots and is fixed,
dots 33 of Color 1 are formed below the dots 34 of Color 2. Therefore, in the forward
scan, an image with Color 2, which is the color of the dots 34 formed at a higher
layer on the recording medium P, being a dominant color is recorded. On the other
hand, in the backward scan, the inks of Colors 1 and 2 are applied in this order,
so dots 33 of Color 1 are formed at a higher layer. Therefore, Color 1 becomes a dominant
color.
[0069] As described above, in the case where the inks are discharged in large amounts, Color
2 becomes the dominant color in forward scans, and Color 1 becomes the dominant color
in backward scans. This difference in dominant color results in a color difference
between the forward and backward scans.
(2) Image Quality Deterioration Resulting from Deviation of Ink Landing Position
[0070] When the recording head is attached at a tilt to the recording apparatus or when
scans performed by the recording head are tilted, the longer the distance between
the discharge opening array units is, the more deviated the landing positions of inks
discharged from the discharge opening array units are.
[0071] Fig. 9A schematically illustrates the landing positions of inks discharged from two
discharge opening array units LG (1), two discharge opening array units LG (2), and
two discharge opening array units LG (3), which respectively discharge inks of different
colors, of a recording head in a case where the above-described tilt does not occur.
Further, Fig. 9B schematically illustrates the landing positions of inks discharged
from the discharge opening array units LG (1), LG (2), and LG (3) in a case where
the above-described tilt occurs in the recording head illustrated in Fig. 9A.
[0072] Figs. 9A and 9B illustrate the recording head including the discharge opening array
units LG (1), LG (2), and LG (3) arranged in the X-direction such that the two discharge
opening array units LG (2) are located between the two discharge opening array units
LG (1) and the two discharge opening array units LG (3) are located between the two
discharge opening array units LG (2). In other words, the distance between the discharge
opening array units LG (1) is the longest, and the distance between the discharge
opening array units LG (3) is the shortest.
[0073] Further, in Figs. 9A and 9B, positions 30 indicate the landing positions of the ink
from the discharge opening array units LG (1), positions 31 indicate the landing positions
of the ink from the discharge opening array units LG (2), and positions 32 indicate
the landing positions of the ink from the discharge opening array units LG (3). In
the present exemplary embodiment, the landing positions of inks discharged from the
discharge opening arrays that include discharge openings 8 specified by ruled lines
or in black among a plurality of discharge openings arranged in the Y-direction in
the discharge opening array units LG (1), LG (2), and LG (3) will be described below.
[0074] As illustrated in Fig. 9A, in the case where no tilt occurs, ink droplets from the
two discharge opening array units LG (1), the two discharge opening array units LG
(2), and the two discharge opening array units LG (3) land at the same intervals as
the intervals at which the discharge openings are located. Thus, the landing positions
of the inks remain the same regardless of the distance between the discharge opening
array units.
[0075] On the other hand, in the case where the tilt occurs, an extent of a deviation of
ink landing positions in the Y-direction varies depending on the distance between
the discharge opening array units, as illustrated in Fig. 9B. For example, in the
case of the discharge opening array units LG (3) located at a relatively short distance
from each other, when the tilt occurs, the landing positions of the inks deviate as
specified by the positions 32 in Fig. 9B, but the deviations are not so significant,
compared with the positions 32 in Fig. 9A. However, in the case of the discharge opening
array units LG (1) located at a relatively long distance from each other, when the
tilt occurs, the landing positions of the inks deviate significantly as specified
by the positions 30 in Fig. 9B, compared with the positions 30 in Fig. 9A.
[0076] As described above, the longer the distance between the discharge opening array units
is, the more the ink landing positions deviate when the tilt occurs, and this causes
a significant impact on image quality deteriorations.
[0077] The arrangement order of the discharge opening array units according to the present
exemplary embodiment is determined in view of (1) the color difference between forward
and backward scans and (2) the image quality deteriorations resulting from deviations
of ink landing positions.
[0078] First, in order to reduce (1) the color difference between forward and backward scans
described above, the cyan ink discharge opening array units LG1 (C1) and LG1 (C2),
the magenta ink discharge opening array units LG1 (M1) and LG1 (M2), the yellow ink
discharge opening array unit LG1 (Y), and the black ink discharge opening array units
LG1 (K1) and LG1 (K2) in the chip 20 in Fig. 6 are symmetrically arranged.
[0079] Specifically, the two magenta ink discharge opening array units LG1 (M1) and LG1
(M2) are situated between the two cyan ink discharge opening array units LG1 (C1)
and LG1 (C2). Further, the two black ink discharge opening array units LG1 (K1) and
LG1 (K2) are situated between the two magenta ink discharge opening array units LG1
(M1) and LG1 (M2). Further, the one yellow ink discharge opening array unit LG1 (Y)
is situated between the two black ink discharge opening array units LG1 (K1) and LG1
(K2).
[0080] Thus, the cyan, magenta, yellow, and black inks are applied in the same order in
both forward and backward scans. Specifically, the cyan, magenta, black, yellow, black,
magenta, and cyan inks are applied in this order in both forward and backward scans.
Thus, as to the cyan, magenta, yellow, and black inks, a color difference between
the forward and backward scans can be reduced.
[0081] Meanwhile, as illustrated in Fig. 6, the light blue ink discharge opening array unit
LG1 (LB) is symmetrically arranged with respect to the cyan ink discharge opening
array units LG1 (C1) and LG1 (C2) and the magenta ink discharge opening array units
LG1 (M1) and LG1 (M2) but asymmetrically arranged with respect to the black ink discharge
opening array units LG1 (K1) and LG1 (K2).
[0082] Specifically, the light blue ink discharge opening array unit LG1 (LB) is situated
between the two cyan ink discharge opening array units LG1 (C1) and LG1 (C2) and between
the two magenta ink discharge opening array units LG1 (M1) and LG1 (M2). Thus, for
example, as to the light blue ink and the cyan ink, the cyan, light blue, and cyan
inks are discharged in this order in both forward and backward scans. Thus, as to
the light blue ink and the cyan ink or as to the light blue ink and the magenta ink,
a color difference between the forward and backward scans can be reduced.
[0083] On the other hand, the light blue ink discharge opening array unit LG1 (LB) is situated
not between the two black ink discharge opening array units LG1 (K1) and LG1 (K2).
In other words, as to the light blue ink and the black ink, the light blue ink discharge
opening array unit LG1 (LB), the black ink discharge opening array unit LG1 (K1),
and the black ink discharge opening array unit LG1 (K2) are arranged in this order
from the left. Thus, the black, black, and light blue inks are discharged in this
order in forward scans, whereas the light blue, black, and black inks are discharged
in this order in backward scans, with respect to the same position on a recording
medium in the X-direction. Thus, when the light blue ink and the black inks are discharged
in large amounts, a color difference between forward and backward scans can occur
between the light blue ink and the black ink.
[0084] However, as described above with reference to Figs. 4A and 4B, in the present exemplary
embodiment, the recording rate (discharge amount) of each color ink is determined
such that the light blue ink and the black ink are not substantially simultaneously
discharged. In other words, substantially no color is reproduced using both the light
blue ink and the black ink in the present exemplary embodiment.
[0085] For example, as illustrated in Fig. 4A, the light blue ink is used while substantially
no black ink is used in the low- to intermediate-densities on the blue line. Further,
the black ink is used while no light blue ink is used in the intermediate- to high-densities.
[0086] Further, as illustrated in Fig. 4B, the light blue ink and the black ink are both
used in the high densities on the yellow line, but the discharge amounts are small.
[0087] As described above, according to the present exemplary embodiment, the light blue
ink and the black ink are not discharged in large amounts to the same region. Thus,
superimposition of dots of the light blue ink and the black ink which is described
above with reference to Fig. 8B is less likely to occur. Accordingly, although the
light blue ink discharge opening array unit LG1 (LB) is asymmetrically situated with
respect to the black ink discharge opening array units LG1 (K1) and LG1 (K2), a color
difference between forward and backward scans is less likely to occur with respect
to the light blue ink and the black ink.
[0088] Meanwhile, as illustrated in Fig. 4A, the light blue ink and the cyan ink can be
used simultaneously in relatively large amounts in the intermediate densities, etc.
on the blue line. In other words, in the present exemplary embodiment, there are many
colors that are reproduced using both the light blue ink and the cyan ink.
[0089] Thus, as to the light blue ink and the cyan ink, a color difference between forward
and backward scans can occur, so that the light blue ink discharge opening array unit
LG1 (LB) is symmetrically arranged with respect to the cyan ink discharge opening
array units LG1 (C1) and LG1 (C2). The same applies to the light blue ink and the
magenta ink.
[0090] In view of the reduction of (1) the color difference between forward and backward
scans alone, the light blue ink discharge opening array unit LG1 (LB) does not have
to be arranged asymmetrically with respect to the two black ink discharge opening
array units LG1 (K1) and LG1 (K2) as illustrated in Fig. 6. In other words, even if
the light blue ink discharge opening array unit LG1 (LB) is arranged in a symmetric
position, i.e., between the two black ink discharge opening array units LG1 (K1) and
LG1 (K2), no color difference between forward and backward scans is likely to occur
with respect to the light blue ink and the black ink as in the present exemplary embodiment.
[0091] However, if the light blue ink discharge opening array unit LG1 (LB) is arranged
between the two black ink discharge opening array units LG1 (K1) and LG1 (K2), the
distance between the two black ink discharge opening array units LG1 (K1) and LG1
(K2) is increased by the light blue ink discharge opening array LG1 (LB). Thus, as
described above in the section "(2) Image Quality Deterioration Resulting from Deviation
of Ink Landing Position", a significant deviation of landing positions of the black
ink can occur. As shown in (Table 1), the black ink has the lowest lightness and is
easy to visually recognize, so that deterioration in image quality which results from
occurrence of landing position deviation can be significant.
[0092] In view of the foregoing point, according to the present exemplary embodiment, the
light blue ink discharge opening array unit LG1 (LB) is arranged not between the two
black ink discharge opening array units LG1 (K1) and LG1 (K2). In this way, the distance
between the black ink discharge opening array units LG1 (K1) and LG1 (K2) is reduced.
This arrangement can reduce to some extent a deviation of landing positions of the
black ink, which is easy to visually recognize, to reduce image quality deteriorations.
As described above, the light blue ink and the black ink are less likely to be used
simultaneously, so the arrangement as described above does not lead to a color difference
between forward and backward scans with respect to the light blue ink and the black
ink.
[0093] The arrangement enables recording with reduced image quality deteriorations resulting
from deviations of ink landing positions while a color difference between forward
and backward scans is reduced.
[0094] While the arrangement in which the two magenta ink discharge opening array units
LG1 (M1) and LG1 (M2) are arranged between the two cyan ink discharge opening array
units LG1 (C1) and LG1 (C2) is described in the first exemplary embodiment, other
arrangements can also be implemented. A similar advantage to that produced by the
present exemplary embodiment can be produced if the two black ink discharge opening
array units LG1 (K1) and LG1 (K2) are arranged between the two cyan ink discharge
opening array units LG1 (C1) and LG1 (C2) and between the two magenta ink discharge
opening array units LG1 (M1) and LG1 (M2) and the light blue ink discharge opening
array unit LG1 (LB) is arranged between the two cyan ink discharge opening array units
LG1 (C1) and LG1 (C2), between the two magenta ink discharge opening array units LG1
(M1) and LG1 (M2), and not between the two black ink discharge opening array units
LG1 (K1) and LG1 (K2). For example, the cyan ink discharge opening array unit LG1
(C1), the magenta ink discharge opening array unit LG1 (M1), the light blue ink discharge
opening array unit LG1 (LB), the black ink discharge opening array unit LG1 (K1),
the yellow ink discharge opening array unit LG1 (Y), the black ink discharge opening
array unit LG1 (K2), the magenta ink discharge opening array unit LG1 (M2), and the
cyan ink discharge opening array unit LG1 (C2) can be arranged in this order from
the left. Even in this case, a color difference between forward and backward scans
is reduced with respect to the light blue ink and the cyan ink, which can be discharged
simultaneously in large amounts, and with respect to the light blue ink and the magenta
ink, which can be discharged simultaneously in large amounts, and the distance between
the two black ink discharge opening array units LG1 (K1) and LG1 (K2) is shortened
to reduce deviations of ink landing positions. It is more desirable, however, to arrange
the two magenta ink discharge opening array units LG1 (M1) and LG1 (M2) between the
two cyan ink discharge opening array units LG1 (C1) and LG1 (C2) or to arrange the
two cyan ink discharge opening array units LG1 (C1) and LG1 (C2) between the two magenta
ink discharge opening array units LG1 (M1) and LG1 (M2), because a color difference
between forward and backward scans with respect to the cyan ink and the magenta ink
can be further reduced.
[0095] In the first exemplary embodiment described above, the arrangement is described in
which the cyan ink discharge opening array unit and the magenta ink discharge opening
array unit each include the discharge opening arrays which respectively have a large
discharge opening diameter and a moderate discharge opening diameter.
[0096] In a second exemplary embodiment, an arrangement will be described in which the cyan
ink discharge opening array unit and the magenta ink discharge opening array unit
each include three discharge opening arrays in total including a discharge opening
array having a small discharge opening diameter in addition to the discharge opening
array having a large discharge opening diameter and the discharge opening array having
a moderate discharge opening diameter.
[0097] Description of similar points to those in the first exemplary embodiment is omitted.
[0098] Fig. 10 is an enlarged view illustrating the Cl chip 20 in the recording head 1 according
to the present exemplary embodiment. Further, Figs. 9A and 9B illustrate the internal
configuration of the cyan ink discharge opening array unit according to the present
exemplary embodiment.
[0099] From a comparison between the Cl chip in Fig. 10 which is used in the present exemplary
embodiment and the Cl chip in Fig. 6 which is used in the first exemplary embodiment,
it is understood that the Cl chip in the present exemplary embodiment is similar to
the Cl chip in the first exemplary embodiment in the arrangement order of discharge
opening array units and the configurations of a light blue ink discharge opening array
unit LG2 (LB), black ink discharge opening array units LG2 (K1) and LG2 (K2), and
a yellow ink discharge opening array unit LG2 (Y).
[0100] The Cl chip used in the present exemplary embodiment is different from the Cl chip
used in the first exemplary embodiment in that cyan ink discharge opening array units
LG2 (C1) and LG2 (C2) and magenta ink discharge opening array units LG2 (M1) and LG2
(M2) each include a discharge opening array including discharge openings 23 having
a relatively small discharge opening diameter in addition to the discharge opening
array including the discharge openings 22 having a large discharge opening diameter
and the discharge opening array including the discharge openings 24 having a moderate
discharge opening diameter.
[0101] Details will be described below.
1. Cyan Ink Discharge Opening Array Unit and Magenta Ink Discharge Opening Array Unit
[0102] The Cl chip 20 according to the present exemplary embodiment includes two cyan ink
discharge opening array units (LG2 (C1), LG2 (C2)). The cyan ink discharge opening
array units LG2 (C1) and LG2 (C2) each include three discharge opening arrays.
[0103] As illustrated in Fig. 11, in the cyan ink discharge opening array unit LG2 (C1),
one of the discharge opening arrays is provided on one side (left side) of the common
liquid chamber 21. This discharge opening array includes the relatively large discharge
openings 22 each of which has a diameter of approximately 16 µm and through which
an ink droplet of approximately 5 pl is discharged. Further, the other two discharge
opening arrays are provided on the other side (right side) of the common liquid chamber
21. One of the two discharge opening arrays includes the moderate discharge openings
24 each of which has a diameter of approximately 12 µm and through which an ink droplet
of approximately 2 pl is discharged, and is situated close to the common liquid chamber
21. The other one of the two discharge opening arrays includes the relatively small
discharge openings 23 each of which has a diameter of approximately 9 µm and through
which an ink droplet of approximately 1 pl is discharged, and is situated far from
the common liquid chamber 21.
[0104] Each of the discharge opening arrays includes 264 discharge openings 22, 23, or 24
arranged at 600-dpi intervals (approximately 42.3 µm) in the Y-direction. Further,
the discharge opening array including the discharge openings 22 having a discharge
opening diameter of approximately 16 µm and the discharge opening array including
the discharge openings 24 having a discharge opening diameter of approximately 12
µm are staggered at 2400-dpi intervals (approximately 10.6 µm) in the Y-direction.
Further, the discharge opening array including the discharge openings 24 having a
discharge opening diameter of approximately 12 µm and the discharge opening array
including the discharge openings 23 having a discharge opening diameter of approximately
9 µm are staggered at 1200-dpi intervals (approximately 21.2 µm) in the Y-direction.
[0105] As described above, cyan ink droplets are discharged in three sizes including 5 pl,
2 pl, and 1 pl so that graininess can be made less visible in a wide range of density
gradations. In the first exemplary embodiment, inks of only two sizes, 5 pl and 2
pl, can be discharged. Thus, even in the reproduction of a low density, 2-pl cyan
ink droplets have to be used, so that formed dots are not so small, and thus graininess
may be visible. However, in the present exemplary embodiment, 1-pl cyan ink droplets
can be used to reproduce a low density, so that the dot size can be decreased and
graininess can be made less visible.
[0106] The cyan ink discharge opening array unit LG2 (C2) is similar to the discharge opening
array unit LG2 (C1) in that the cyan ink discharge opening array unit LG2 (C2) includes
a discharge opening array having a discharge opening diameter of approximately 16
µm, a discharge opening array having a discharge opening diameter of approximately
12 µm, and a discharge opening array having a discharge opening diameter of approximately
9 µm. The cyan ink discharge opening array unit LG2 (C2) is different from the discharge
opening array unit LG2 (C1) in that the arrangement of the three discharge opening
arrays in the X-direction in the discharge opening array unit LG2 (C2) is opposite
to the arrangement in the discharge opening array units LG2 (C1). Further, the two
discharge opening arrays including the discharge openings of the same diameter in
the discharge opening array units LG2 (C1) and LG2 (C2) are staggered at 1200-dpi
intervals (approximately 21.2 µm) in the Y-direction.
[0107] Further, the magenta ink discharge opening array unit LG2 (M1) has a similar configuration
to the configuration of the cyan ink discharge opening array unit LG2 (C1), and the
magenta ink discharge opening array unit LG2 (M2) has a similar configuration to the
configuration of the cyan ink discharge opening array unit LG2 (C2).
2. Arrangement Order of Discharge Opening Array Units in Chip
[0108] As illustrated in Fig. 10, in the chip 20 according to the present exemplary embodiment,
the cyan ink discharge opening array unit LG2 (C1), the magenta ink discharge opening
array unit LG2 (M1), the light blue ink discharge opening array unit LG2 (LB), the
black ink discharge opening array unit LG2 (K1), the yellow ink discharge opening
array unit LG2 (Y), the black ink discharge opening array unit LG2 (K2), magenta ink
discharge opening array unit LG2 (M2), and the cyan ink discharge opening array unit
LG2 (C2) are arranged in this order from the left.
[0109] Specifically, in the present exemplary embodiment, the two black ink discharge opening
array units LG2 (K1) and LG2 (K2) are arranged between the two cyan ink discharge
opening array units LG2 (C1) and LG2 (C2) and between the two magenta ink discharge
opening array units LG2 (M1) and LG2 (M2), as in the first exemplary embodiment. Further,
the light blue ink discharge opening array unit LG2 (LB) is arranged between the two
cyan ink discharge opening array units LG2 (C1) and LG2 (C2), between the two magenta
ink discharge opening array units LG2 (M1) and LG2 (M2), and not between the two black
ink discharge opening array units LG2 (K1) and LG2 (K2).
[0110] Thus, in the present exemplary embodiment, a color difference between forward and
backward scans is reduced with respect to the light blue ink and the cyan ink, which
can be discharged simultaneously in large amounts, and with respect to the light blue
ink and the magenta ink, which can be discharged simultaneously in large amounts.
Further, the distance between the two black ink discharge opening array units LG2
(K1) and LG2 (K2) is shortened to reduce image quality deteriorations resulting from
a deviation of landing positions of low-lightness inks.
[0111] In the above-described exemplary embodiments, an ink that satisfies the conditions
that the light blue ink has a hue angle h3 between hue angles h1 and h2 of the cyan
ink and the magenta ink and has a higher lightness L3 than each of lightnesses L1
and L2 of the cyan ink and the magenta ink is used as the light blue ink. However,
as a result of studies conducted by the present inventors, it was found that it was
desirable to satisfy
and
where h' is the hue angle of blue in a case where the cyan ink and the magenta ink
of equal amounts are mixed, and L' is the surface lightness of a recording medium
used. This disclosure is not restricted to the inks being of a particular color, such
that:
the cyan ink is an example of a first ink;
the magenta ink is an example of a second ink;
the light blue ink is an example of a third ink;
the black ink is an example of a fourth ink; and
the yellow ink is an example of a fifth ink.
[0112] In order to suitably reproduce the blue hue with the light blue ink, the hue of the
light blue ink is desirably close to the hue of the blue ink as much a possible rather
than to the hues of the cyan ink and the magenta ink.
[0113] In (formula 1), h' - h1 corresponds to a difference between the hue angles of blue
and cyan. Accordingly, the term h1 + (h' - h1)/2 in (formula 1) corresponds to a hue
shifted from the cyan hue toward the blue hue by a half of the difference between
the hue angles of blue and cyan. In other words, the term h1 + (h' - h1)/2 in (formula
1) corresponds to the middle hue between the cyan hue and the blue hue.
[0114] Further, h2 - h' corresponds to a difference between the hue angles of magenta and
blue. Accordingly, the term h2 - (h2 - h')/2 in (formula 1) corresponds to a hue shifted
from the magenta hue toward the blue hue by a half of the difference between the hue
angles of magenta and blue. In other words, the term h2 - (h2 - h')/2 in (formula
1) corresponds to the middle hue between the magenta hue and the blue hue.
[0115] Accordingly, when the hue angle h3 of the light blue ink satisfies (formula 1), this
indicates that the hue of the light blue ink is located between the middle hue of
the cyan hue and the blue hue and the middle hue of the magenta hue and the blue hue.
[0116] Further, in the exemplary embodiments, the blue hue is reproduced with the light
blue ink in the low to intermediate densities or with the cyan ink and the magenta
ink in the intermediate to high densities, as illustrated in Fig. 4A.
[0117] If the lightness of the light blue ink is excessively high, a gap arises between
the lightness of the light blue ink and the lightnesses of the cyan ink and the magenta
ink. This can make graininess of the cyan ink and the magenta ink visible when the
cyan ink and the magenta ink are applied onto the light blue ink. Thus, the lightness
of the light blue ink is desirably closer to the lightnesses of the cyan ink and the
magenta ink than to the surface lightness of a recording medium.
[0118] In (formula 2), the term L' - L3 corresponds to a difference in lightness between
a recording medium and the light blue ink, and the term L3 - L1 corresponds to a difference
in lightness between the light blue ink and the cyan ink. Accordingly, when the lightness
L3 of the light blue ink satisfies (formula 2), this indicates that the difference
in lightness between the recording medium and the light blue ink is greater than the
difference in lightness between the light blue ink and the cyan ink, i.e., the lightness
of the light blue ink is closer to the lightness of the cyan ink than to the surface
lightness of the recording medium.
[0119] Further, the term L3 - L2 in (formula 3) corresponds to a difference in lightness
between the light blue ink and the magenta ink. Thus, when the lightness L3 of the
light blue ink satisfies (formula 3), this indicates that the difference in lightness
between the recording medium and the light blue ink is greater than the difference
in lightness between the light blue ink and the magenta ink, i.e., the lightness of
the light blue ink is closer to the lightness of the magenta ink than to the surface
lightness of the recording medium, because discharged ink droplets are less likely
to be impacted by airflows.
Other Embodiments
[0120] Embodiment(s) of the present invention can also be realized by a computer of a system
or apparatus that reads out and executes computer executable instructions (e.g., one
or more programs) recorded on a storage medium (which may also be referred to more
fully as a 'non-transitory computer-readable storage medium') to perform the functions
of one or more of the above-described embodiment(s) and/or that includes one or more
circuits (e.g., application specific integrated circuit (ASIC)) for performing the
functions of one or more of the above-described embodiment(s), and by a method performed
by the computer of the system or apparatus by, for example, reading out and executing
the computer executable instructions from the storage medium to perform the functions
of one or more of the above-described embodiment(s) and/or controlling the one or
more circuits to perform the functions of one or more of the above-described embodiment(s).
The computer may comprise one or more processors (e.g., central processing unit (CPU),
micro processing unit (MPU)) and may include a network of separate computers or separate
processors to read out and execute the computer executable instructions. The computer
executable instructions may be provided to the computer, for example, from a network
or the storage medium. The storage medium may include, for example, one or more of
a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of
distributed computing systems, an optical disk (such as a compact disc (CD), digital
versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card,
and the like.
[0121] Further, while the exemplary embodiments are described above in which there are only
a few colors to be reproduced using both the light blue ink and the black ink while
there are many colors to be reproduced using both the light blue ink and the cyan
ink or both the light blue ink and the magenta ink, other embodiments can be implemented.
If the condition that the number of colors to be reproduced using both the light blue
ink and the black ink is smaller than the number of colors to be reproduced using
both the light blue ink and the cyan ink and is also smaller than the number of colors
to be reproduced using both the light blue ink and the magenta ink is satisfied, an
advantage can be produced by a similar arrangement to that according to the present
exemplary embodiment. If the above-described condition is satisfied, a color difference
between forward and backward scans is less likely to occur between the light blue
ink and the black ink, compared to between the light blue ink and the cyan ink and
between the light blue ink and the magenta ink.
[0122] Further, while the exemplary embodiments are described above in which each discharge
opening array unit includes a plurality of discharge opening arrays, each discharge
opening array unit may consist of only one discharge opening array. For example, every
discharge opening array unit may consist of only one discharge opening array including
discharge openings through which 5-pl ink droplets are discharged.
[0123] It should be noted, however, that in a discharge opening array unit including two
or more discharge opening arrays having a large discharge opening diameter, e.g.,
in the yellow ink discharge opening array unit LG1 (Y) illustrated in Fig. 6, strong
airflows can be generated near the discharge opening array unit due to many large-sized
ink droplets being discharged therefrom. If a discharge opening array unit including
a discharge opening array having a small discharge opening diameter, e.g., the light
blue ink discharge opening array unit LG1 (LB) illustrated in Fig. 6, is provided
near such a discharge opening array unit, small-sized ink droplets of 1 pl are significantly
impacted by the airflows, so that a deviation of ink landing positions can occur in
the discharge opening array having a small discharge opening diameter and lead to
image quality deteriorations.
[0124] On the other hand, in the arrangements of the discharge opening array units according
to the first and second exemplary embodiments, the discharge opening array unit LG1
(Y) is not provided next to the discharge opening array unit LG1 (LB). Instead, the
discharge opening array unit LG1 (K1) is provided between the discharge opening array
unit LG1 (Y) and the discharge opening array unit LG1 (LB) as illustrated in Fig.
6 so that image quality deteriorations resulting from the airflows are reduced. Specifically,
since the discharge opening array unit LG1 (K1) includes only one discharge opening
array having a large discharge opening diameter, strong airflows are less likely to
occur in the vicinity. Further, since the discharge opening array unit LG1 (K1) includes
no discharge opening array having a small discharge opening diameter, ink droplets
discharged from the discharge opening array unit LG1 (K1) are less likely to be impacted
by the airflows even if strong airflows are generated as a result of discharging from
the discharge opening array unit LG1 (Y).
[0125] The recording head according to an exemplary embodiment of the present invention
is capable of reducing a color difference between forward and backward scans while
reducing image quality deteriorations resulting from deviations of ink landing positions.
[0126] While the present invention has been described with reference to exemplary embodiments,
it is to be understood that the invention is not limited to the disclosed exemplary
embodiments. The scope of the following claims is to be accorded the broadest interpretation
so as to encompass all such modifications and equivalent structures and functions.
1. A recording head (1) comprising:
a plurality of discharge opening array means (LG1) arranged side by side and including
at least:
two first discharge opening array means (LG1(C1), LG1(C2)) for discharging an ink
of a first color (C);
two second discharge opening array means (LG1(M1), LG1(M2)) for discharging an ink
of a second color (M);
a third discharge opening array means (LG1(LB)) for discharging an ink of a third
color (LB); and
two fourth discharge opening array means (LG1(K1), LG1(K2)) for discharging an ink
of a fourth color (K), wherein:
h1 < h3 < h2,
L3 > L1 > L4, and
L3 > L2 > L4
are satisfied, where:
h1 is a hue angle of the first color (C),
L1 is a lightness of the first color (C),
h2 is a hue angle of the second color (M),
L2 is a lightness of the second color (M),
h3 is a hue angle of the third color (LB),
L3 is a lightness of the third color (LB),
L4 is a lightness of the fourth color (K), and
wherein the third discharge opening array means (LG1(LB)) is the only discharge opening
means, among the plurality of discharge opening array means (LG1), for discharging
the ink of the third color (LB),
wherein the plurality of discharge opening array means (LG1) is arranged in such a
manner that the one third discharge opening array means (LG1(LB)) is located between
the two first discharge opening array means (LG1(C1), LG1(C2)), between the two second
discharge opening array means (LG1(M1), LG1(M2)), and not between the two fourth discharge
opening array means (LG1(K1), LG1(K2)), and
wherein:
is satisfied, where h' is a hue angle of a color reproduced by a mixture of equal
amounts of the ink of the first color (C) and the ink of the second color (M).
2. The recording head (1) according to claim 1, wherein:
and
are satisfied, where L' is a lightness of a color of a surface of a recording medium.
3. The recording head (1) according to claim 1 or claim 2, wherein:
the first color is cyan (C),
the second color is magenta (M),
the third color is light blue (LB), and
the fourth color is black (K).
4. The recording head (1) according to any preceding claim, wherein the number of colors
to be reproduced using both the ink of the third color (LB) and the ink of the fourth
color (K) is smaller than the number of colors to be reproduced using both the ink
of the first color (C) and the ink of the third color (LB) and is smaller than the
number of colors to be reproduced using both the ink of the second color (M) and the
ink of the third color (LB).
5. The recording head (1) according to any preceding claim, wherein the plurality of
discharge opening array means (LG1) is arranged in such a manner that the two fourth
discharge opening array means (LG1(K1), LG1(K2)) are located between the two first
discharge opening array means (LG1(C1), LG1(C2)) and between the two second discharge
opening array means (LG1(M1), LG1(M2)).
6. The recording head (1) according to any preceding claim, wherein the plurality of
discharge opening array means (LG1) is arranged in such a manner that the two second
discharge opening array means (LG1(M1), LG1(M2)) are located between the two first
discharge opening array means (LG1(C1), LG1 (C2)) .
7. The recording head (1) according to any preceding claim,
wherein the plurality of discharge opening array means (LG1) further includes one
fifth discharge opening array means (LG1(Y)) for discharging an ink of a fifth color
(Y), wherein
h5 < h1, and
L5 > L4
are satisfied, where h5 is a hue angle of the fifth color (Y), and L5 is a lightness
of the fifth color (Y), and
wherein the plurality of discharge opening array means (LG1) is arranged in such a
manner that the one fifth discharge opening array means (LG1(Y)) is located between
the two fourth discharge opening array means (LG1(K1), LG1(K2)) .
8. The recording head (1) according to claim 7, wherein the fifth color is yellow (Y).
9. The recording head (1) according to claim 7 or claim 8, wherein the plurality of discharge
opening array means (LG1) consists of only eight discharge opening array means which
are:
the two first discharge opening array means (LG1(C1), LG1 (C2)),
the two second discharge opening array means (LG1(M1), LG1(M2)),
the one third discharge opening array means (LG1(LB)),
the two fourth discharge opening array means (LG1(K1), LG1(K2)), and
the one fifth discharge opening array means (LG1(Y)).
10. The recording head (1) according to any one of claims 7 to 9,
wherein each of the plurality of discharge opening array means (LG1) includes at least
one of:
a first discharge opening array including a discharge opening having a first diameter
and arranged in a predetermined direction,
a second discharge opening array including a discharge opening having a second diameter
smaller than the first diameter and arranged in the predetermined direction, and
a third discharge opening array including a discharge opening having a third diameter
smaller than the second diameter and arranged in the predetermined direction,
wherein each of the two first discharge opening array means (LG1(C1), LG1(C2)) includes
a third discharge opening array,
wherein each of the two second discharge opening array means (LG1(M1), LG1(M2)) includes
a third discharge opening array,
wherein the one third discharge opening array means (LG1(LB)) includes at least a
third discharge opening array and includes one or more first discharge opening array(s)
of fewer than N,
wherein each of the two fourth discharge opening array means (LG1(K1), LG1(K2)) includes
one or more first discharge opening array(s) of fewer than N, includes a second discharge
opening array, and does not include a third discharge opening array, and
wherein the one fifth discharge opening array means (LG1(Y)) includes two or more
first discharge opening array(s) of N (N ≥ 2) and does not include a third discharge
opening array.
11. The recording head (1) according to claim 10, wherein each of the two first discharge
opening array means (LG1(C1), LG1(C2)) consists of only three discharge opening arrays
which are the one third discharge opening array, the one second discharge opening
array, and the one first discharge opening array,
wherein each of the two second discharge opening array means (LG1(M1), LG1(M2)) consists
of only three discharge opening arrays which are the one third discharge opening array,
the one second discharge opening array, and the one first discharge opening array,
wherein the one third discharge opening array means (LG1(LB)) consists of only four
discharge opening arrays which are the two third discharge opening arrays and the
two second discharge opening arrays,
wherein each of the two fourth discharge opening array means (LG1(K1), LG1(K2)) consists
of only two discharge opening arrays which are the one second discharge opening array
and the one first discharge opening array, and
wherein the one fifth discharge opening array means (LG1(Y)) consists of only the
two first discharge opening arrays.
12. The recording head (1) according to any preceding claim, wherein each of the plurality
of discharge opening array means (LG1) includes one liquid chamber (21).
13. The recording head (1) according to any preceding claim, wherein the plurality of
discharge opening array means (LG1) is provided in one chip (20).
14. The recording head (1) according to any preceding claim, wherein the plurality of
discharge opening array means (LG1) is provided in a same nozzle plate.
15. An inkjet recording apparatus (1000) comprising:
a recording head (1) according to any preceding claim; and
control means (300) for controlling a recording operation by causing the recording
head (1) to discharge the inks.
16. The inkjet recording apparatus (1000) according to claim 15, wherein the control means
(300) controls the recording operation by causing the recording head (1) to discharge
the inks while the recording head (1) performs forward and backward scans.
1. Aufzeichnungskopf (1), umfassend:
mehrere Ausstoßöffnungsarrayeinrichtungen (LG1), die nebeneinander angeordnet sind
und zumindest umfassen:
zwei erste Ausstoßöffnungsarrayeinrichtungen (LG1(C1), LG1(C2)) zum Ausstoßen einer
Tinte einer ersten Farbe (C);
zwei zweite Ausstoßöffnungsarrayeinrichtungen (LG1(M1), LG1(M2)) zum Ausstoßen einer
Tinte einer zweiten Farbe (M);
eine dritte Ausstoßöffnungsarrayeinrichtung (LG1(LB)) zum Ausstoßen einer Tinte einer
dritten Farbe (LB); und
zwei vierte Ausstoßöffnungsarrayeinrichtungen (LG1(K1), LG1(K2)) zum Ausstoßen einer
Tinte einer vierten Farbe (K), wobei
h1 <h3<h2,
L3 > L1 > L4, und
L3 > L2 > L4
erfüllt sind, wobei
h1 ein Farbtonwinkel der ersten Farbe (C) ist,
L1 eine Helligkeit der ersten Farbe (C) ist,
h2 ein Farbtonwinkel der zweiten Farbe (M) ist,
L2 eine Helligkeit der zweiten Farbe (M) ist,
h3 ein Farbtonwinkel der dritten Farbe (LB) ist,
L3 eine Helligkeit der dritten Farbe (LB) ist,
L4 eine Helligkeit der vierten Farbe (K) ist, und
wobei die dritte Ausstoßöffnungsarrayeinrichtung (LG1(LB)) unter den mehreren Ausstoßöffnungsarrayeinrichtungen
(LG1) die einzige Ausstoßöffnungseinrichtung zum Ausstoßen der dritten Farbe (LB)
ist,
wobei die mehreren Ausstoßöffnungsarrayeinrichtungen (LG1) derart angeordnet ist,
dass die eine dritte Ausstoßöffnungsarrayeinrichtung (LG1(LB)) zwischen den beiden
ersten Ausstoßöffnungsarrayeinrichtungen (LG1(C1), LG1(C2)), zwischen den beiden zweiten
Ausstoßöffnungsarrayeinrichtungen (LG1(M1), LG1(M2)) und nicht zwischen den beiden
vierten Ausstoßöffnungsarrayeinrichtungen (LG1(K1), LG1 (K2)) positioniert ist, und
wobei:
erfüllt ist, wobei h' ein Farbtonwinkel einer Farbe ist, die durch eine Mischung
gleicher Mengen der Tinte in der ersten Farbe (C) und der Tinte in der zweiten Farbe
(M) reproduziert wird.
2. Aufzeichnungskopf (1) nach Anspruch 1, wobei
und
erfüllt sind, wobei L' eine Helligkeit einer Farbe einer Oberfläche eines Aufzeichnungsmediums
ist.
3. Aufzeichnungskopf (1) nach Anspruch 1 oder Anspruch 2, wobei
die erste Farbe Cyan (C) ist,
die zweite Farbe Magenta (M) ist,
die dritte Farbe Hellblau (LB) ist, und
die vierte Farbe Schwarz (K) ist.
4. Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche, wobei die Anzahl Farben,
die unter Verwendung sowohl der Tinte der dritten Farbe (LB) als auch der Tinte der
vierten Farbe (K) zu reproduzieren sind, kleiner ist als die Anzahl Farben, die unter
Verwendung sowohl der Tinte der ersten Farbe (C) als auch der Tinte der dritten Farbe
zu reproduzieren sind, und kleiner ist als die Anzahl Farben, die unter Verwendung
sowohl der Tinte der zweiten Farbe (M) als auch der Tinte der dritten Farbe (LB) zu
reproduzieren ist.
5. Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche, wobei die mehreren
Ausstoßöffnungsarrayeinrichtungen (LG1) derart angeordnet sind, dass die beiden vierten
Ausstoßöffnungsarrayeinrichtungen (LG1(K1), LG1(K2)) zwischen den beiden ersten
Ausstoßöffnungsarrayeinrichtungen (LG1(C1), LG1(C2)) und zwischen den beiden zweiten
Ausstoßöffnungsarrayeinrichtungen (LG1(M1), LG1(M2)) positioniert sind.
6. Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche, wobei die mehreren
Ausstoßöffnungsarrayeinrichtungen (LG1) derart angeordnet sind, dass die beiden zweiten
Ausstoßöffnungsarrayeinrichtungen (LG1(M1), LG1(M2)) zwischen den beiden ersten
Ausstoßöffnungsarrayeinrichtungen (LG1(C1), LG1(C2)) positioniert sind.
7. Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche,
wobei die mehreren Ausstoßöffnungsarrayeinrichtungen (LG1) weiterhin eine fünfte Ausstoßöffnungsarrayeinrichtung
(LG1(Y)) zum Ausstoßen einer Tinte einer fünften Farbe (Y) umfasst, wobei
h5 < h1, und
L5 > L4
erfüllt sind, wobei h5 ein Farbtonwinkel der fünften Farbe (Y) ist und L5 eine Helligkeit
der fünften Farbe (Y) ist, und
wobei die mehreren Ausstoßöffnungsarrayeinrichtungen (LG1) derart angeordnet sind,
dass die eine fünfte Ausstoßöffnungsarrayeinrichtung (LG1(Y)) zwischen den beiden
vierten Ausstoßöffnungsarrayeinrichtungen (LG1(K1), LG1(K2)) positioniert ist.
8. Aufzeichnungskopf (1) nach Anspruch 7, wobei die fünfte Farbe Gelb (Y) ist.
9. Aufzeichnungskopf (1) nach Anspruch 7 oder Anspruch 8, wobei die mehreren Ausstoßöffnungsarrayeinrichtungen
(LG1) aus nur acht Ausstoßöffnungsarrayeinrichtungen bestehen, nämlich:
den beiden ersten Ausstoßöffnungsarrayeinrichtungen (LG1(C1), LG1(C2)),
den beiden zweiten Ausstoßöffnungsarrayeinrichtungen (LG1(M1), LG1(M2)),
der einen dritten Ausstoßöffnungsarrayeinrichtung (LG1(LB)),
den beiden vierten Ausstoßöffnungsarrayeinrichtungen (LG1(K1), LG1(K2)), und
der einen fünften Ausstoßöffnungsarrayeinrichtung (LG1(Y)).
10. Aufzeichnungskopf (1) nach einem der Ansprüche 7 bis 9,
wobei die mehreren Ausstoßöffnungsarrayeinrichtungen (LG1) jeweils mindestens eines
der Folgenden enthalten:
ein erstes Ausstoßöffnungsarray mit einer Ausstoßöffnung, die einen ersten Durchmesser
hat und in einer vorbestimmten Richtung angeordnet ist,
ein zweites Ausstoßöffnungsarray mit einer Ausstoßöffnung, die einen zweiten Durchmesser
hat, welcher kleiner ist als der erste Durchmesser, und die in der vorbestimmten Richtung
angeordnet ist,
ein drittes Ausstoßöffnungsarray mit einer Ausstoßöffnung, die einen dritten Durchmesser
hat, welcher kleiner ist als der zweite Durchmesser, und die in der vorbestimmten
Richtung angeordnet ist,
wobei die beiden ersten Ausstoßöffnungsarrayeinrichtungen (LG1(C1), LG1(C2)) jeweils
ein drittes Ausstoßöffnungsarray beinhalten,
wobei die beiden zweiten Ausstoßöffnungsarrayeinrichtungen (LG1(M1), LG1(M2)) jeweils
ein drittes Ausstoßöffnungsarray beinhalten,
wobei die eine dritte Ausstoßöffnungsarrayeinrichtung (LG1(LB)) mindestens ein drittes
Ausstoßöffnungsarray und eine oder mehrere, aber weniger als N erste Ausstoßöffnungsarrayeinrichtung(en)
enthält,
wobei die beiden vierten Ausstoßöffnungsarrayeinrichtungen (LG1(K1), LG1(K2)) jeweils
ein oder mehreres, aber weniger als N, erste Ausstoßöffnungsarray(s) enthalten, ein
zweites Ausstoßöffnungsarray enthalten und kein drittes Ausstoßöffnungsarray enthalten,
und
wobei die eine fünfte Ausstoßöffnungsarrayeinrichtung (LG1(Y)) zwei oder mehrere erste
Ausstoßöffnungsarrays einer Anzahl N (N≥2) enthält und kein drittes Ausstoßöffnungsarray
enthält.
11. Aufzeichnungskopf (1) nach Anspruch 10, wobei die beiden ersten Ausstoßöffnungsarrayeinrichtungen
(LG1(C1), LG1(C2)) jeweils aus nur drei Ausstoßöffnungsarrays bestehen, und zwar aus
dem einen dritten Ausstoßöffnungsarray, dem einen zweiten Ausstoßöffnungsarray, und
dem einen ersten Ausstoßöffnungsarray,
wobei die beiden zweiten Ausstoßöffnungsarrayeinrichtungen (LG1(M1), LG1(M2)) jeweils
aus nur drei Ausstoßöffnungsarrays bestehen, und zwar dem einen dritten Ausstoßöffnungsarray,
dem einen zweiten Ausstoßöffnungsarray, und dem einen ersten Ausstoßöffnungsarray,
wobei die eine dritte Ausstoßöffnungsarrayeinrichtung (LG1(LB)) aus nur vier Ausstoßöffnungsarrays
besteht, und zwar den beiden dritten Ausstoßöffnungsarrays und den beiden zweiten
Ausstoßöffnungsarrays,
wobei die beiden vierten Ausstoßöffnungsarrayeinrichtungen (LG1(K1), LG1(K2)) jeweils
aus nur zwei Ausstoßöffnungsarrays bestehen, und zwar dem einen zweiten Ausstoßöffnungsarray
und dem einen ersten Ausstoßöffnungsarray, und
wobei die eine fünfte Ausstoßöffnungsarrayeinrichtung (LG1(Y)) aus nur den beiden
ersten Ausstoßöffnungsarrays besteht.
12. Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche, wobei die mehreren
Ausstoßöffnungsarrayeinrichtungen (LG1) jeweils eine Flüssigkeitskammer (21) enthalten.
13. Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche, wobei die mehreren
Ausstoßöffnungsarrayeinrichtungen (LG1) in einem Chip (20) vorgesehen sind.
14. Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche, wobei die mehreren
Ausstoßöffnungsarrayeinrichtungen (LG1) in einer gleichen Düsenplatte vorgesehen sind.
15. Tintenstrahlaufzeichnungsvorrichtung (1000), umfassend:
einen Aufzeichnungskopf (1) nach einem der vorhergehenden Ansprüche; und
eine Aufzeichnungseinrichtung (300) zum Steuern einer Aufzeichnungsverarbeitung durch
Veranlassen des Aufzeichnungskopfs (1), die Tinten auszustoßen.
16. Tintenstrahlaufzeichnungsvorrichtung (1000) nach Anspruch 15, wobei die Steuereinrichtung
(300) die Aufzeichnungsverarbeitung steuert, indem sie den Aufzeichnungskopf (1) veranlasst,
die Tinten auszustoßen, während der Aufzeichnungskopf (1) Abtastungen vorwärts und
rückwärts durchführt.
1. Tête d'enregistrement (1), comprenant :
une pluralité de moyens formant réseau d'ouvertures de décharge (LG1) disposés côte
à côte et comprenant au moins :
deux premiers moyens formant réseau d'ouvertures de décharge (LG1(C1), LG1(C2)) destinés
à décharger une encre d'une première couleur (C) ;
deux deuxièmes moyens formant réseau d'ouvertures de décharge (LG1(M1), LG1(M2)) destinés
à décharger une encre d'une deuxième couleur (M) ;
un troisième moyen formant réseau d'ouvertures de décharge (LG1(LB)) destiné à décharger
une encre d'une troisième couleur (LB) ; et
deux quatrièmes moyens formant réseau d'ouvertures de décharge (LG1(K1), LG1(K2))
destinés à décharger une encre d'une quatrième couleur (K),
dans laquelle les expressions :
h1 < h3 < h2,
L3 > L1 > L4, et
L3 > L2 > L4
sont satisfaites, dans lesquelles :
h1 est un angle de teinte de la première couleur (C),
L1 est une luminosité de la première couleur (C),
h2 est un angle de teinte de la deuxième couleur (M),
L2 est une luminosité de la deuxième couleur (M),
h3 est un angle de teinte de la troisième couleur (LB),
L3 est une luminosité de la troisième couleur (LB),
L4 est une luminosité de la quatrième couleur (K), et
dans laquelle le troisième moyen formant réseau d'ouvertures de décharge (LG1(LB))
est l'unique moyen d'ouvertures de décharge, parmi la pluralité de moyens formant
réseau d'ouvertures de décharge (LG1), destiné à décharger l'encre de la troisième
couleur (LB),
dans laquelle la pluralité de moyens formant réseau d'ouvertures de décharge (LG1)
est disposée d'une manière telle que l'unique troisième moyen formant réseau d'ouvertures
de décharge (LG1(LB)) est situé entre les deux premiers moyens formant réseau d'ouvertures
de décharge (LG1(C1), LG1(C2)), entre les deux deuxièmes moyens formant réseau d'ouvertures
de décharge (LG1(M1), LG1(M2)), et non entre les deux quatrièmes moyens formant réseau
d'ouvertures de décharge (LG1(K1), LG1(K2)), et
dans laquelle l'expression :
est satisfaite, dans laquelle h' est un angle de teinte d'une couleur reproduite
par un mélange de quantités égales de l'encre de la première couleur (C) et de l'encre
de la deuxième couleur (M).
2. Tête d'enregistrement (1) selon la revendication 1, dans laquelle les expressions
:
et
sont satisfaites, dans lesquelles L' est une luminosité d'une couleur d'une surface
d'un support d'enregistrement.
3. Tête d'enregistrement (1) selon la revendication 1 ou la revendication 2, dans laquelle
:
la première couleur est le cyan (C),
la deuxième couleur est le magenta (M),
la troisième couleur est le bleu clair (LB), et
la quatrième couleur est le noir (K).
4. Tête d'enregistrement (1) selon l'une quelconque des revendications précédentes, dans
laquelle le nombre de couleurs à reproduire au moyen à la fois de l'encre de la troisième
couleur (LB) et de l'encre de la quatrième couleur (K) est inférieur au nombre de
couleurs à reproduire au moyen à la fois de l'encre de la première couleur (C) et
de l'encre de la troisième couleur (LB) et est inférieur au nombre de couleurs à reproduire
au moyen à la fois de l'encre de la deuxième couleur (M) et de l'encre de la troisième
couleur (LB).
5. Tête d'enregistrement (1) selon l'une quelconque des revendications précédentes, dans
laquelle la pluralité de moyens formant réseau d'ouvertures de décharge (LG1) est
disposée d'une manière telle que les deux quatrièmes moyens formant réseau d'ouvertures
de décharge (LG1(K1), LG1(K2)) sont situés entre les deux premiers moyens formant
réseau d'ouvertures de décharge (LG1(C1), LG1(C2)) et entre les deux deuxièmes moyens
formant réseau d'ouvertures de décharge (LG1(M1), LG1(M2)).
6. Tête d'enregistrement (1) selon l'une quelconque des revendications précédentes, dans
laquelle la pluralité de moyens formant réseau d'ouvertures de décharge (LG1) est
disposée d'une manière telle que les deux deuxièmes moyens formant réseau d'ouvertures
de décharge (LG1(M1), LG1(M2)) sont situés entre les deux premiers moyens formant
réseau d'ouvertures de décharge (LG1(C1), LG1(C2)).
7. Tête d'enregistrement (1) selon l'une quelconque des revendications précédentes,
dans laquelle la pluralité de moyens formant réseau d'ouvertures de décharge (LG1)
comprend en outre un cinquième moyen formant réseau d'ouvertures de décharge (LG1(Y))
destiné à décharger une encre d'une cinquième couleur (Y), où les expressions
h5 < h1, et
L5 > L4
sont satisfaites, dans lesquelles h5 est un angle de teinte de la cinquième couleur
(Y), et L5 est une luminosité de la cinquième couleur (Y), et
dans laquelle la pluralité de moyens formant réseau d'ouvertures de décharge (LG1)
est disposée d'une manière telle que l'unique cinquième moyen formant réseau d'ouvertures
de décharge (LG1(Y)) est situé entre les deux quatrièmes moyens formant réseau d'ouvertures
de décharge (LG1(K1), LG1(K2)).
8. Tête d'enregistrement (1) selon la revendication 7, dans laquelle la cinquième couleur
est le jaune (Y).
9. Tête d'enregistrement (1) selon la revendication 7 ou la revendication 8, dans laquelle
la pluralité de moyens formant réseau d'ouvertures de décharge (LG1) n'est constituée
que de huit moyens formant réseau d'ouvertures de décharge qui sont :
les deux premiers moyens formant réseau d'ouvertures de décharge (LG1(C1), LG1(C2)),
les deux deuxièmes moyens formant réseau d'ouvertures de décharge (LG1(M1), LG1(M2)),
l'unique troisième moyen formant réseau d'ouvertures de décharge (LG1(LB)),
les deux quatrièmes moyens formant réseau d'ouvertures de décharge (LG1(K1), LG1(K2)),
et
l'unique cinquième moyen formant réseau d'ouvertures de décharge (LG1(Y)).
10. Tête d'enregistrement (1) selon l'une quelconque des revendications 7 à 9,
dans laquelle chacun de la pluralité de moyens formant réseau d'ouvertures de décharge
(LG1) comprend au moins l'un :
d'un premier réseau d'ouvertures de décharge comprenant une ouverture de décharge
ayant un premier diamètre et disposée dans une direction prédéterminée,
d'un deuxième réseau d'ouvertures de décharge comprenant une ouverture de décharge
ayant un deuxième diamètre inférieur au premier diamètre et disposée dans la direction
prédéterminée, et
d'un troisième réseau d'ouvertures de décharge comprenant une ouverture de décharge
ayant un troisième diamètre inférieur au deuxième diamètre et disposée dans la direction
prédéterminée,
dans laquelle chacun des deux premiers moyens formant réseau d'ouvertures de décharge
(LG1(C1), LG1(C2)) comprend un troisième réseau d'ouvertures de décharge,
dans laquelle chacun des deux deuxièmes moyens formant réseau d'ouvertures de décharge
(LG1(M1), LG1(M2)) comprend un troisième réseau d'ouvertures de décharge,
dans laquelle l'unique troisième moyen formant réseau d'ouvertures de décharge (LG1(LB))
comprend au moins un troisième réseau d'ouvertures de décharge et comprend un ou plusieurs
premiers réseaux d'ouvertures de décharge en nombre inférieur à N,
dans laquelle chacun des deux quatrièmes moyens formant réseau d'ouvertures de décharge
(LG1(K1), LG1(K2)) comprend un ou plusieurs premiers réseaux d'ouverture de décharge
en nombre inférieur à N, comprend un second réseau d'ouvertures de décharge, et ne
comprend pas de troisième réseau d'ouvertures de décharge, et
dans laquelle l'unique cinquième moyen formant réseau d'ouvertures de décharge (LG1(Y))
comprend deux ou plus de deux premiers réseaux d'ouvertures de décharge en nombre
N (N ≥ 2) et ne comprend pas de troisième réseau d'ouvertures de décharge.
11. Tête d'enregistrement (1) selon la revendication 10, dans laquelle chacun des deux
premiers moyens formant réseau d'ouvertures de décharge (LG1(C1), LG1(C2)) n'est constitué
que de trois réseaux d'ouvertures de décharge qui sont ledit troisième réseau d'ouvertures
de décharge, ledit deuxième réseau d'ouvertures de décharge et ledit premier réseau
d'ouvertures de décharge,
dans laquelle chacun des deux deuxièmes moyens formant réseau d'ouvertures de décharge
(LG1(M1), LG1(M2)) n'est constitué que de trois réseaux d'ouverture de décharges qui
sont ledit troisième réseau d'ouvertures de décharge, ledit deuxième réseau d'ouvertures
de décharge et ledit premier réseau d'ouvertures de décharge,
dans laquelle l'unique troisième moyen formant réseau d'ouvertures de décharge (LG1(LB))
n'est constitué que de quatre réseaux d'ouvertures de décharge qui sont les deux troisièmes
réseaux d'ouvertures de décharge et les deux deuxièmes réseaux d'ouvertures de décharge,
dans laquelle chacun des deux quatrièmes moyens formant réseau d'ouvertures de décharge
(LG1(K1), LG1(K2)) n'est constitué que de deux réseaux d'ouvertures de décharge qui
sont ledit deuxième réseau d'ouvertures de décharge et ledit premier réseau d'ouvertures
de décharge, et
dans laquelle l'unique cinquième moyen formant réseau d'ouvertures de décharge (LG1(Y))
n'est constitué que des deux premiers réseaux d'ouvertures de décharge.
12. Tête d'enregistrement (1) selon l'une quelconque des revendications précédentes, dans
laquelle chacun de la pluralité de moyens formant réseau d'ouvertures de décharge
(LG1) comprend une chambre de liquide (21).
13. Tête d'enregistrement (1) selon l'une quelconque des revendications précédentes, dans
laquelle la pluralité de moyens formant réseau d'ouvertures de décharge (LG1) est
disposée dans une puce (20).
14. Tête d'enregistrement (1) selon l'une quelconque des revendications précédentes, dans
laquelle la pluralité de moyens formant réseau d'ouvertures de décharge (LG1) est
disposée dans une même plaque de buses.
15. Appareil d'enregistrement à jet d'encre (1000), comprenant :
une tête d'enregistrement (1) selon l'une quelconque des revendications précédentes
; et
un moyen de commande (300) destiné à commander une opération d'enregistrement en amenant
la tête d'enregistrement (1) à décharger les encres.
16. Appareil d'enregistrement à jet d'encre (1000) selon la revendication 15, dans lequel
le moyen de commande (300) commande l'opération d'enregistrement en amenant la tête
d'enregistrement (1) à décharger les encres tandis que la tête d'enregistrement (1)
effectue des balayages vers l'avant et vers l'arrière.